After a four year build at McConaghy Boats in Zhu Hai, China, the fuel efficient 42.5m trimaran Adastra has been launched into the Pearl River.
Designed by UK-based John Shuttleworth Yacht Designs, Adastra is the second largest trimaran yacht ever built (the 61m White Rabbit being the biggest), and is the fourth largest powered multihull in the world.
With full ocean-going performance, the yacht was originally conceived as a stripped-out cruising yacht for Hong Kong owners Anto and Elaine Marden, who wanted to undertake long-range cruising, but once the requirement for luxury accommodation was added into the equation the weight went up and the design changed to compensate.
'It takes the power trimaran concept further than has ever been attempted before,' says Shuttleworth. 'The challenge of turning this concept into a viable luxury yacht has taken us to further research and to develop new thinking on stability and comfort at sea for this type of craft.'
McConaghy Boats was chosen for the construction of this revolutionary design because of its proximity to Hong Kong and its experience with advanced composite construction. The Chinese yard is a subsidiary of the Australian builder - renowned for its race-winning sailing yachts - and the Zhu Hai facility specialises in high quality carbon structures.
The hull of Adastra is constructed from a glass and Kevlar sandwich using Corecell foam with the superstructure moulded from a carbon fibre laminate on a Nomex honeycomb core. All the hull structures were resin infused to ensure high quality and reduce weight and virtually every part of the yacht is custom built. McConaghy has used its expertise in carbon laminates to create lightweight hatches, portholes and hinges and rather than using ceramics for the toilet bowls, these have also been moulded in carbon.
Onboard, in an interior designed by Jepsen Designs of Hong Kong, there is accommodation for nine guests and a crew of six. The master suite is located aft with access from the deck saloon and the guest cabins are forward of the engine compartment. Forward again are the crew cabins and the galley. The focus of the guest areas is the deck saloon, which is almost circular in shape, and has panoramic windows. The main helm station is at the aft end of the saloon where there is seating for two on a raised plinth to give a view over the top of the main superstructure. Behind this is the open cockpit with sofas on both sides and the open deck running aft where there is stowage for a 4.9m tender. A second 3.1m tender is stowed in the garage space below the aft deck, which has a door that hinges out to create a bathing platform.
Adastra is powered by a single Caterpillar C18 disel that produces 1,150hp. This drives through a conventional shaft and propeller system and to facilitate harbour manoeuvring there is a Yanmar 110hp diesel engine in each of the sponsons. The main engine is expected to produce a top speed of 22.5 knots, and at a 17 knot cruise speed the consumption is a miserly 120 litres per hour, and the range 4,000 nautical miles.
Once she has been delivered Adastra's owners plan to cruise her in the Pacific.